Wide Area Networks, particularly the Internet, has been suffering from storage and computational overloads of increased traffic, which problems are growing at an alarming rate.
A resource reservation protocol (RSVP) requires that reservation and confirmation of a network resource occur on every node through which data will pass, every time a connection is made, which will tend to create long delays while a connection is being established. In RSVP and MultiProtocol Label Switching (MPLS) networks, as the network grows in size, the number of connections and the number of transactions for the reservation that a node must handle will grow, which will require a correspondingly large computational power at each node, and the network may be unable to handle the necessary connections and transactions.
Recently, applications running on Internet Protocol (IP) infrastructure are evolving to require high-bandwidth and real-time transfer of data. To differentiate these high-demand applications from conventional applications such as e-mail downloads and WEB page transactions, a virtual path (simply “path” hereafter) that guarantees Quality of Service (QoS) attributes, such as bandwidth, delay and jitter, can be used. The sender of the data specifies the path on which the data flow will be allocated and then sends the data on that path to have a guaranteed QoS.
One prior art method establishes pre-set paths, for example as set forth in U.S. Pat. No. 6,108,304, to Hajime et al, dated Jun. 8, 1998. The pre-set path is established between a first-hop node and a last hop node of a Wide Area Network (WAN), such as the Internet, and can be used for any path that starts from a terminal that directly connects to the first-hop node and ends at a terminal that directly or indirectly connects to the last-hop node. The many terminals that directly connect to the first-hop node and the last-hop node can share the pre-set paths when establishing their own paths.
As used herein, Edge nodes of the network, edge nodes of sub-networks, edge nodes of work-groups, and gateways are examples of a first-hop node and a last-hop node of a Wide Area Network, which are in contrast to transit nodes that are along the path between the first-hop node and the last-hop node.
Routing information is exchanged between the first-hop node and the last hop node of a Wide Area Network in IETF, Multi-protocol Label Switching Architecture, RFC3031, January 2001. The first-hop node needs a path table linking the IP address of the destination terminal to a pre-set path. The source terminal sends a packet with a destination IP address to the first-hop node. The first-hop node uses the destination IP address to extract a path from its path table and then sends the packet through the selected pre-set path.
U.S. Pat. No. 5,933,425, issued to Iwata on Aug. 3, 1999, selects a first path to a destination in response to a connection request that specifies multiple Quality of Service (QoS) parameters. If the transmission of the first signal along the first path is unsuccessful, then a second path is selected according to a database. The pre-set paths are kept current as to QoS.
U.S. Pat. No. 6,094,682, issued to Nagasawa on Jul. 25, 2000, specifies a pre-set path that is available at log-on of a terminal. The originating network element, which is the starting point of a path, transmits a path trace value to the next network element, which path trace value has an identifier of the element which transmits the path trace value. The receiving element changes the identifier of the path trace value to its own identifier and retransmits the modified path trace value to the next element, etc. up to an end point. Each element holds cross-connect information and transmits to a network management system that constructs paths using the cross-connect information.
U.S. Pat. No. 5,751,971, issued to Dobbins et al on May 12, 1998, has multiple router interfaces assigned the same IP network address, creating an IP work group and allowing a host to be relocated anywhere in the work group without requiring reconfiguration of the host. A single address is used for several physical networks.
U.S. Pat. No. 6,256,295 B1 to Callon, dated Jul. 3, 2001, has a system for determining a plurality of minimally-overlapping paths between a source node and a destination node in a network. If the first path and the second path overlap, the system modifies at least one path to minimize the overlap of the paths to lessen the likelihood that a failure in one path will cause a failure of the other path.
There is a need for an improved set-up of QoS paths.